Very large Mannheim-type slide rule. Single slider. Scales on slide rule face identical with above, with addition of a triple radius line of numbers along the bottom edge. No scales on edges or reverse. Presumably used in a museum exhibit and as a teaching tool.
Материал
"PAT. JUNE 5, 1900; KEUFFEL & ESSER CO. N.Y.; MADE IN U.S.A.; MODEL 100"
